A rectangular eddy current array sensor can be employed to inspect cracks of metal structure quantificationally

but it is often influenced by lift-off effect. Through setting up finite element model of rectangular eddy current array sensor

analyze response characteristics of sensor on lift-off distance

besides

crack inspecting platform is established

and influence of lift-off diatance on crack inspecting capability of sensor is investigated. It’s shown that the sensor is very sensitive to life-off effect

which must be suppressed in crack inspecting process

and crack inspecting capability is weakened sharply when lift-off distance increased

therefore

lift-off distance should be decreased as small as possible in crack inspecting process.